| Nanosize materials have been one of hot spots these years in the materialscience field for their unique properties. Nowadays home and abroad many of"nano paint"are actually nanosize particles modified coating, for example, SiO2,TiO2 and ZnO are used in architectual coating to improve weathering resistance.Conventional polymer latex is still taken as matrix and nanosize pigment orfiller is added in the kind of coating. Properties of coating are not improvedmuch because no other new matrixes replace the conventional ones whichcannot be defined as nanosize coating practically. Real nanosize coating iscomposed of nanosize polymer latex as film forming material.On the basic of briefly summarizing the research and applicaition literatureof building coatings and nano-composite building coatings in domestic andoverseas, we systematically studied nucleation mechanism, dynamics ofsoap-free latex polymerization and etc. Then we presented a creative approachof nanosize coating composed of nanosize self-emulsified waterborne polyesterlatex applying soap-free latex polymerization.One of the two components is hydrophobic polyester. Besides, redoxinitiating system was introduced as to reduce temperature of the reactioneffectively. This component which formed the core part provided waterresistance, adhesive attraction for the coating. The other component ishydrophilic acrylic polyester in which main monomers included MMA, BMA,MAA. The hydrophilic polyester was taken as shell part and was compatiblewith pigments and fillers. After the two components were made respectively,they were put together proportionally in deioned water with fix pH index underthe condition of high-speed mix around. Finally block copolymer was gainedthrough a series of reactions. Extention of phase separation was limited owingto influence of chemical bonds among chains in block copolymer system. Inmicrophase small micro-region and excellent conglutination endowed blockcopolymer with fine transparence and mechanical performance. Copolymerincluding acrylic block would have good weather durability if reactions werecarried away suitably. This experiment adopted anion system so as to made thefinal products. Anion made from polar monomer such as methacrylic resin hadweak alkalescence and couldn't trigger copolymerization of hydrocarbonmonomers. Then for the aim of obtaining block copolymer includinghydrocarbon and acrylic resin non-polar chains were formed firstly and weutilized produced polymer anion to trigger copolymerization of acrylicmonomers. Emulsions had good calcium ion stability and freeze-thaw stabilityas well as high solid content. The solid content of the three emulsions wasrespectively about 40%,45% and 50%. In view of some requirements that architectural coatings should have gooddirt resistance, scrub resistance and be dried at ambient conditions as well as becheap, the structures and properties of the copolymers are characterized bymeans of DSC, IR and TEM. Results indicated that average particle diameter oflattices for nanosize close primer, interior wall finish and exterior wall finishwere about 65nm, 80nm and 20nm respectively. Particles were monodisperse.From the IR spectra of three latices we can find latent apices of groups in thetwo components which showed the two block components had been linked bychemical bond. The fact that curves of latices each had only one glass transitiontemperature demonstrated block copolymer obtained molecule scalecompatibility. Usually high glass transition temperature means high hardnessand mechanical intensity, improved scratch resistance, low flexility andtractility. As minimum film-forming temperature was considered, glasstransition temperature couldn't be too high. Many factors influence glasstransition temperature of polymer, such as molecular weight and its distribution,flexility of molecular chain, interaction between molecular chain and etc.Flexility of molecular chain and crosslinking are dominating factors whichinfluence glass transition temperature of polymer, and the former is related toproportion of soft/hard monomer while the latter is related to crosslinkingmonomer dosage. Glass transition temperature of latices of primer, interior wallfinish and exterior wall finish were respectively 136.681℃, 7.752℃, 8.087℃. We proposed film-forming mechanism of soap-free latex in the following:film-forming course included pileup of granules, syncretize of granules andpervasion of polymer chain ends. In the respect of rheology latices arepseudplastic liquid. In the paper preparation of close primer, finish for interior and exteriorwall were also studied. Firstly templets were made according to state coatingstandards. Then water-resistance, alkaline resistance and other items wereexamined. Results showed that water-resistance and alkaline resistance ofprimer were beyond the state standards as well as adhesive attraction was not...
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